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| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 15 |
| 3 | 57 |
| 4 | 182 |
| 5 | 790 |
| 6 | 3217 |
| 7 | 13298 |
| 8 | 56866 |
| 9 | 254689 |
| 10 | 1128121 |
| 11 | 5106701 |
| 12 | 23266331 |
| 13 | 107019385 |
| 14 | 494689488 |
| 15 | 2306491761 |
| 16 | 10758057302 |
| 17 | 50548874979 |
[3,15,57,182,790,3217,13298,56866,254689,1128121, 5106701,23266331,107019385,494689488,2306491761, 10758057302,50548874979] |